1. Field of the Invention
The present invention is generally related to a method for positioning a marine vessel and, more particularly, a method for maintaining the position of a marine vessel at a selected global position, measured in terms of longitude and latitude, and a selected heading, measured as a compass angle.
2. Description of the Related Art
As will be described below, those skilled in the art are familiar with many different types of marine propulsion systems, including outboard motors, stemdrive systems, trolling motors, and devices which are rotatable about steering axes which extend downwardly through a bottom or lower surface of the hull of a marine vessel. In addition, those skilled in the art are familiar with various types of marine vessel maneuvering systems that can be used to maneuver a marine vessel during docking procedures. Those skilled in the art are also familiar with various types of joystick applications, some of which are associated with the control of a marine vessel.
U.S. Pat. No. 5,108,325, which issued to Livingston et al. on Apr. 28, 1992, discloses a boat propulsion device that mounts through a hole in a bottom surface of a boat. The engine is positioned inside the boat and the propeller drive is positioned under a bottom surface of the boat. The propulsion device includes a mounting assembly, a steering assembly rotatably connecting the drive to the mounting assembly for steering the propeller drive under the boat, a trimming assembly swingingly connecting the drive to the steering assembly for trimming/tilting of the propeller drive under the boat at any steered position, and a driveshaft means providing a drive connection between the engine and the propeller drive at any steered and trimmed position.
U.S. Pat. No. 5,386,368, which issued to Knight on Jan. 31, 1995, describes an apparatus for maintaining a boat in a fixed position. The apparatus includes an electric trolling motor disposed to produce a thrust to pull the boat, a steering motor disposed to affect the orientation of the electric trolling motor, a position deviation detection unit, and a control circuit. The position deviation detection unit detects a deviation in the position of the boat from the desired position and transmits signals indicative of a deviation distance (the distance from the boat to the desired position) and a return heading (the direction of the desired position from the boat) to the control unit.
U.S. Pat. No. 5,735,718, which issued to Ekwall on Apr. 7, 1998, describes a drive unit for a boat having an engine with a flywheel surrounded by a flywheel casing, a propeller drive housing connected to, but electrically insulated from, the flywheel casing, and an input shaft for the propeller drive housing which is driven and electrically insulated from the flywheel.
U.S. Pat. No. 5,755,605, which issued to Asberg on May 26, 1998, describes a propeller drive unit. Installation in a boat has two propeller drive units which extend out through individual openings in the bottom of a V-bottomed boat, so that the legs are inclined relative to each other. The leg of one drive unit can be set to turn the boat in one direction at the same time as the leg of the other drive unit can be set to turn the boat in the opposite direction, so that the horizontal counteracting forces acting on the legs cancel each other, while the vertical forces are added to each other to trim the running position of the boat in the water.
U.S. Pat. No. 6,142,841, which issued to Alexander et al. on Nov. 7, 2000, discloses a waterjet docking control system for a marine vessel. A maneuvering control system is provided which utilizes pressurized liquid at three or more positions of a marine vessel in order to selectively create thrust that moves the marine vessel into desired positions and according to chosen movements. A source of pressurized liquid, such as a pump or a jet pump propulsion system, is connected to a plurality of distribution conduits which, in turn, are connected to a plurality of outlet conduits. Electrical embodiments of the system can utilize one or more pairs of impellers to cause fluid to flow through outlet conduits in order to provide thrust on the marine vessel.
U.S. Pat. No. 6,230,642, which issued to McKenney et al. on May 15, 2001, describes an autopilot based steering and maneuvering system for boats. The steering system uses a specially integrated autopilot that remains engaged unless the operator is actively commanding the boat to change course. For example, in a boat in which steering is performed using a joystick, course changes can be affected simply by moving the joystick. The movement automatically disengages the autopilot, allowing the operator to achieve the course change. When the operator has completed the course change and released the joystick, a centering spring returns it to a neutral position and the autopilot automatically re-engages.
U.S. Pat. No. 6,234,853, which issued to Lanyi et al. on May 22, 2001, discloses a simplified docking method and apparatus for a multiple engine marine vessel. A docking system is provided which utilizes the marine propulsion unit of a marine vessel, under the control of an engine control unit that receives command signals from a joystick or push button device, to respond to a maneuver command from the marine operator. The docking system does not require additional propulsion devices other than those normally used to operate the marine vessel under normal conditions. The docking and maneuvering system uses two marine propulsion units to respond to an operator's command signal and allows the operator to select forward or reverse commands in combination with clockwise or counterclockwise rotational commands either in combination with each other or alone.
International Patent Application WO 03/042036, which was filed by Arvidsson on Nov. 8, 2002, describes a remote control system for a vehicle. It comprises a primary heading sensor fixedly attached to the vehicle, the primary heading sensor being adapted to detect a reference heading, a remote control unit comprising a steering input manipulator, the remote control unit being either portable by a user or rotationally attached to the vehicle relative to a marine axis of the vehicle, the remote control unit being adapted to communicate steering input data to a steering computer programmed to process the steering input data into steering commands and to communicate the steering commands to a steering mechanism of the vehicle. The remote control unit comprises a secondary heading sensor which is synchronized with the primary heading sensor with respect to the reference heading, and the steering input data includes information of an active position of the steering input manipulator relative to the reference heading, the active position of the steering input manipulator determining the desired direction of travel of the vehicle regardless of the orientation of the remote control unit relative to the main axis of the vehicle.
U.S. Pat. No. 6,357,375, which issued to Ellis on Mar. 19, 2002, describes a boat thruster control apparatus. A watercraft is provided with a bow thruster and a stem thruster. A control panel in the helm has a thruster control stick for controlling each thruster and a HOLD device associated with each control stick. When the boat is brought into the desired position, for example, alongside a dock, the HOLD device can be pushed for one or both of the thrusters. When the HOLD is pushed, a signal is sent to a CPU to ignore any changes in position of the corresponding thruster control stick and to maintain the current amount of thrust in the corresponding thruster.
International Patent Application WO 03/093102, which was filed by Arvidsson et al. on Apr. 29, 2003, describes a method of steering a boat with double outboard drives and a boat having double outboard drives. The method of steering a planing V-bottomed boat with double individually steerable outboard drive units with underwater housings, which extend down from the bottom of the boat, is described. When running at planing speed straight ahead, the underwater housings are set with “toe-in” (i.e. inclined toward each other with opposite angles of equal magnitude relative to the boat centerline). When turning, the inner drive unit is set with a greater steering angle than the outer drive unit.
U.S. Pat. No. 6,386,930, which issued to Moffet on May 14, 2002, describes a differential bucket control system for waterjet boats. The boat has a reversing bucket for control forward/reverse thrust and a rotatable nozzle for controlling sideward forces. A bucket position sensor is connected to the reversing bucket, and the bucket is controlled using the output of the position sensor to enable the bucket to be automatically moved to a neutral thrust position. A joystick with two axes of motion may be used to control both the bucket and the nozzle. The joystick has built in centering forces that automatically return it to a neutral position, causing both the bucket and nozzle to return to their neutral positions.
U.S. Pat. No. 6,431,928, which issued to Aarnivuo on Aug. 13, 2002, describes an arrangement and method for turning a propulsion unit. The propeller drive arrangement includes an azimuthing propulsion unit, a power supply, a control unit, and a sensor means. An operating means is provided for turning the azimuthing propulsion unit in relation to the hull of the vessel for steering the vessel in accordance with a steering command controlled by the vessel's steering control device. The operating means also includes a second electric motor for turning the azimuthing propulsion unit via a mechanical power transmission that is connected to the second electric motor.
U.S. Pat. No. 6,447,349, which issued to Fadeley et al. on Sep. 10, 2002, describes a stick control system for a waterjet boat. The boat has a reversing bucket for controlling forward/reverse thrust and a rotatable nozzle for controlling sideward forces. A bucket position sensor is connected to the reversing bucket, and the bucket is controlled using the output of the position sensor to enable the bucket to be automatically moved to a neutral thrust position. Similarly, a nozzle position sensor is connected to the nozzle, and the nozzle is controlled using the output of the nozzle position sensor so that the nozzle may be automatically returned to a zero sideward force position.
U.S. Pat. No. 6,511,354, which issued to Gonring et al. on Jan. 28, 2003, discloses a multipurpose control mechanism for a marine vessel. The mechanism allows the operator of a marine vessel to use the mechanism as both a standard throttle and gear selection device and, alternatively, as a multi-axis joystick command device. The control mechanism comprises a base portion and a lever that is movable relative to the base portion along with a distal member that is attached to the lever for rotation about a central axis of the lever. A primary control signal is provided by the multi-purpose control mechanism when the marine vessel is operated in a first mode in which the control signal provides information relating to engine speed and gear selection. The mechanism can also operate in a second or docking mode and provide first, second, and third secondary control signals relating to desired maneuvers of the marine vessel.
U.S. Pat. No. 6,623,320, which issued to Hedlund on Sep. 23, 2003, describes a drive means in a boat. A boat propeller drive with an underwater housing which is connected in a fixed manner to a boat hull and has tractor propellers arranged on that side of the housing facing ahead is described. Arranged in that end portion of the underwater housing facing astern is an exhaust discharge outlet for discharging exhaust gases from an internal combustion engine connected to the propeller drive.
U.S. patent application Ser. No. 10/181,215, which was filed by Varis on Jan. 26, 2001, describes a motor unit for a ship. The invention relates to a propulsion unit arrangement for a ship and includes a motor unit comprising a motor housing which is arranged in the water and which comprises a motor and any control means relating thereto, as well as a propeller which is arranged at a motor shaft. The motor unit comprises an electric motor for which the cooling is arranged to take place via the surface of the motor's whole circumference through the motor's casing structure directing into the water which surrounds the unit.
U.S. Pat. No. 6,705,907, which issued to Hedlund on Mar. 16, 2004, describes a drive means in a boat. A boat propeller drive has an underwater housing which is connected in a fixed manner to a boat hull and has tractor propellers arranged on that side of the housing facing ahead. In the rear edge of the underwater housing, a rudder blade is mounted for pivoting about a vertical rudder axis.
U.S. Pat. No. 6,712,654, which issued to Putaansuu on Mar. 30, 2004, describes a turning of a propulsion unit. The arrangement for moving and steering a vessel includes a propulsion unit having a chamber positioned outside the vessel equipment for rotating a propeller arranged in connection with the chamber, and a shaft means connected to the chamber for supporting the chamber in a rotatable manner at the hull of the vessel. At least one hydraulic motor is used for turning the shaft means in relation to the hull of the vessel for steering the vessel. The arrangement also includes means for altering the rotational displacement of the hydraulic engine.
U.S. Pat. No. 6,783,410, which issued to Florander et al. on Aug. 31, 2004, describes a drive means in a boat which has an underwater housing which is solidly joined to a boat hull and has pulling propellers on the forward facing side of the housing. At the aft edge of the underwater housing, a rudder is mounted, comprising a first rudder blade mounted in the underwater housing and a second rudder blade mounted on the aft edge of the first rudder blade.
U.S. patent application Ser. No. 10/831,962, which was filed by McKenney et al. on Apr. 26, 2004, describes an autopilot-based steering and maneuvering system for boats. The steering system uses a specially integrated autopilot that remains engaged unless the operator is actively commanding the boat to change course. For example, in a boat in which steering is performed using a joystick, course changes can be effected simply by moving the joystick.
U.S. Pat. No. 6,942,531, which issued to Fell et al. on Sep. 13, 2005, describes a joystick control system for a modified steering system for small boat outboard motors. A joystick controller for modified steering systems for boats with outboard motors is described. The system uses a directional nozzle for the jet output that is attached to a control cable system. This cable turns the directional nozzle, which causes the thrust of the jet output to turn the boat. Thus, the boat can be steered without having to turn the entire motor. The system also has a reversing cup to change direction. The system uses a joystick that connects to a set of actuators, which in turn, connect to the directional nozzle, reverse cup and throttle. In this way the joystick can control the movement of the boat in any direction. The joystick can be used with a conventional motor as well.
U.S. Pat. No. 6,952,180, which issued to Jonsson et al. on Oct. 4, 2005, describes a method and apparatus for determination of position. It is based on a selection and storing of a current position as a waypoint if the following criteria are fulfilled: the current distance of the position along the road from the previous waypoint is greater than a first parameter X or the distance of the position along the road from the previous waypoint is greater than a second parameter Y, where Y is less than X and the deviation between the current traveling direction of the object and the direction established by the connection of the last two waypoints is greater than a third parameter Z and the speed of the object is greater than a minimum speed S. The stored waypoints allow a determination of the traveling direction which is advantageous for localization of vehicles driving on parallel one-way lanes.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
A presentation, titled “Compact Azipod Propulsion on DP Supply Vessels”, was given by Strand et al. at the Thrusters Session of the Dynamic Positioning Conference held in Oslo, Norway on Sep. 18-19, 2001. At that presentation, ABB Marine introduced a product called the Compact Azipod in the offshore supply vessel market on a series of three multifunctional platform supply/ROV vessels. High efficiency, improved maneuverability and station keeping capability, reliability and overall cost effectiveness have been the key criteria for the solutions and overall system design.
A presentation, titled “New Thruster Concept for Station Keeping and Electric Propulsion”, was delivered at the Drives Session of the Dynamic Positioning Conference held at Helsinki, Finland on Sep. 18-19, 2001. The presenters were Adnanes et al. After ten years and 300,000 operation hours of experience with Azipod for propulsion and dynamic positioning, the Compact Azipod has been developed to meet market demand for podded thruster units in the power range of 0.4 to 5 MW. High reliability, power efficiency, and life cycle cost efficiency has been the target for this new thruster concept for station keeping and propulsion.
A presentation, titled “Dynamically Positioned and Thruster Assisted Positioned Moored Vessels”, was provided by Professor Asgeir J. Sorensen of the Department of Marine Technology at the Norwegian University of Science and Technology in Trondheim, Norway. In that presentation, various applications of dynamically positioned vessels are described. In addition, several different control systems are illustrated in relation to the use of Azipod propulsion devices.